Artificial bone template selection system, artificial bone template display system, artificial bone template storage system and artificial bone template recording medium

ABSTRACT

An artificial bone template selection system includes a template data storage system in which template data representing a plurality of templates representing a plurality of artificial bones of different shapes is stored. A bone shape measuring system measures the shape of bone to be replaced by artificial bone on the basis of bone image data representing an image including the bone to be replaced by artificial bone. A prospective template selection system selects at least one template the shape of which substantially conforms to the shape of the bone to be replaced by artificial bone as measured by the bone shape measuring system out of the plurality of templates represented by the template data.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to an artificial bone template selectionsystem which selects an artificial bone template suitable for the partof bone to be replaced by artificial bone out of a plurality ofartificial bone templates prepared in advance. This invention furtherrelates to an artificial bone template display system which displaysartificial bone templates which have been prepared, an artificial bonetemplate storage system which stores a plurality of artificial bonetemplates prepared in advance, and an artificial bone template recordingmedium for recording thereon artificial bone templates.

[0003] 2. Description of the Related Art

[0004] In the orthopedic surgery, the oral surgery and the like, when apatient loses a part of a bone due to disease or accident or by asurgical removal as treatment for malignant tumor, the lost part of thebone has been replaced by his or her own bone of another part.

[0005] Recently, artificial bone (artificial hard tissue) of stainlesssteel, cobalt-chrome series alloy, metal such as titanium, aluminum orzirconium, oxide of these metals, ceramic such as apatite, or compositematerial of these materials has been put into practical use assubstitution for the lost part of the bone.

[0006] Artificial bone which is to be embedded in place of the lost partof the bone is produced on the basis of a standard model which isselected, on the basis of the shape of the part to be replaced by theartificial bone, out of a plurality of standard models which have beenprepared, in advance, in different shapes.

[0007] Conventionally, the standard models are stored in the form ofreal templates representing the contours of the standard models (e.g.,templates formed of transparent plastic sheets), and the real templatesare superposed on an image of the lost part of the bone in sequence andwhether each of the templates conforms to the lost part of the bone isvisually checked.

[0008] However, since the standard models are prepared at intervals of 1mm of the diameter of the bone head (the head of the bone) or the lengthof the bone shaft or the bone holder and at intervals of 1° of the anglebetween the bone shaft and the bone holder, the number of the standardmodels or the real templates is numerous, and accordingly, to select onetemplate in the conventional way is a time-consuming and labor-consumingprocess.

[0009] Further, since being manually superposed on the image of the lostpart of the bone in a limited time interval, each template cannot beaccurately aligned with the image of the lost part and an optimalstandard model or template cannot be constantly selected.

[0010] Further, since numerous templates must be kept at hand,management of the templates is troublesome.

SUMMARY OF THE INVENTION

[0011] In view of the foregoing observations and description, theprimary object of the present invention is to provide an artificial bonetemplate selection system which can efficiently select an artificialbone template suitable for the part of bone to be replaced by artificialbone out of a plurality of artificial bone templates prepared inadvance.

[0012] Another object of the present invention is to provide anartificial bone template display system which displays artificial bonetemplates in such a manner that a suitable template can be selected in ashorter time, and management of templates can be facilitated.

[0013] Still another object of the present invention is to provide atemplate data storage system which stores electronic data on thetemplates in such a manner that a suitable template can be selected in ashorter time.

[0014] Still another object of the present invention is to provide acomputer-readable recording medium which stores electronic data on thetemplates in such a manner that a suitable template can be selected in ashorter time.

[0015] In accordance with a first aspect of the present invention, thereis provided an artificial bone template selection system comprising atemplate data storage means in which template data representing aplurality of templates representing a plurality of artificial bones ofdifferent shapes is stored, a bone shape measuring means which measuresthe shape of bone to be replaced by artificial bone on the basis of boneimage data representing an image including the bone to be replaced byartificial bone, and a prospective template selection means whichselects, as a prospective template, at least one template the shape ofwhich substantially conforms to the shape of the bone to be replaced byartificial bone as measured by the bone shape measuring means out of theplurality of templates represented by the template data.

[0016] Preferably, there are provided a display means which displays thebone image representing the shape of the bone to be replaced by theartificial bone and an image of the prospective template(s) selected bythe prospective template selection means and a display control meanswhich causes the display means to display the bone image and the imageof the prospective template superposed one on another.

[0017] In accordance with a second aspect of the present invention,there is provided an artificial bone template selection systemcomprising a template data storage means in which template datarepresenting a plurality of templates representing a plurality ofartificial bones of different shapes is stored, a bone image displaymeans which displays the bone image representing the shape of the boneto be replaced by the artificial bone, a feature point designating meanswhich designates on the bone image displayed by the bone image displaymeans a feature point representing the shape of the bone, a bone shapespecifying means which specifies the shape of the bone on the basis ofthe feature point designated by the feature point designating means, anda prospective template selection means which selects, as a prospectivetemplate, at least one template the shape of which substantiallyconforms to the shape of the bone specified by the bone shape specifyingmeans out of the plurality of templates represented by the templatedata.

[0018] The artificial bone template selection system in accordance withthe second aspect of the present invention differs from that of thefirst aspect of the present invention in that the former specifies theshape of the bone to be replaced by the artificial bone on the basis ofa feature point designated on the image of the bone displayed by thedisplay means whereas the latter specifies the shape of the bone to bereplaced by the artificial bone on the basis of the bone image data.

[0019] As the feature point representing the shape of the bone, thecenter of the bone head, the edge of the bone head, the longitudinalends of the bone shaft and the bone holder, and the like may be used. Bydesignating the center and the edge of the bone head, the diameter ofthe bone head can be specified, and by designating the longitudinal endsof the bone shaft and the bone holder, the lengths of the bone shaft andthe bone holder and the angle therebetween can be specified. Further,when the diameter of the bone head, the lengths of the bone shaft andthe bone holder and the angle therebetween are specified, the overallshape of the bone can be specified.

[0020] Preferably there are provided a display means which displays animage of the prospective template(s) selected by the prospectivetemplate selection means and a display control means which causes thedisplay means to display the bone image and the image of the prospectivetemplate superposed one on another.

[0021] When the bone image and the image of the prospective template aredisplayed superposed one on another in the artificial bone templateselection system in accordance with the first or second aspect of thepresent invention, it is preferred that an image processing means whichcarries out image processing on at least one of the images displayed bythe display means so that their shapes can be more clearly discriminatedbe provided, and the image processed by the image processing means isdisplayed in the processed condition.

[0022] The expression “so that their shapes can be more clearlydiscriminated” means “so that discrimination between the shapes of theprospective templates is facilitated” (in the case where a plurality ofprospective templates are selected) as well “so that discriminationbetween the shapes of the prospective template and the bone image isfacilitated”.

[0023] In the artificial bone template selection system in accordancewith the first or second aspect of the present invention, it ispreferred that an order information output means which outputs, forinstance, a data file on information for ordering artificial bonecorresponding to the template selected by the prospective templateselection means, e.g., maker, model number, number, delivery time, placeof delivery, and the like, be provided.

[0024] The information for ordering the artificial bone need not be forall the prospective templates selected by the prospective templateselection means but may be for only a final template which is finallyselected from the prospective templates selected by the prospectivetemplate selection means.

[0025] The template data used in the artificial bone template selectionsystem in accordance with the first or second aspect of the presentinvention is preferably prepared not only for storing images of thetemplates as electronic data but also for facilitating retrieval andshape matching. For example, the template data preferably comprises animage file in which a plurality of pieces of image data eachrepresenting one template are recorded and a shape data file in which aplurality of pieces of shape data (e.g., vector data) each representinga feature of the shape of a template are recorded in correlation withthe image data for the template.

[0026] The template data comprising the image data and the shape datamay be provided recorded on a computer-readable recording medium.

[0027] In the artificial bone template selection system in accordancewith the first aspect of the present invention, one or more prospectivetemplates, the shape of which substantially conforms to the shape of thebone to be replaced, can be automatically selected without visuallychecking whether each of the templates conforms to the bone or manuallysuperposing each of the templates on the image of bone, whereby one ormore standard artificial bone can be selected easily in a short time.

[0028] Further, when the bone image and the image of the prospectivetemplate are displayed superposed one on another, whether theprospective template is really suitable for the bone to be replaced canbe judged observing the superposed image. In this case, since the numberof the prospective templates is limited by the automatic selection, atemplate most optimal to the bone can be easily and quickly selected.

[0029] In the artificial bone template selection system in accordancewith the second aspect of the present invention, one or more prospectivetemplates, the shape of which substantially conforms to the shape of thebone to be replaced, can be automatically selected even if the bone istoo complicated in shape for the artificial bone template selectionsystem in accordance with the first aspect of the present invention toselect a template suitable for the bone.

[0030] As in the artificial bone selection system in accordance with thefirst aspect of the present invention, when the bone image and the imageof the prospective template are displayed superposed one on another,whether the prospective template is really suitable for the bone to bereplaced can be judged observing the superposed image. In this case,since the number of the prospective templates is limited by theautomatic selection, a template most optimal to the bone can be easilyand quickly selected.

[0031] Further, in both the artificial bone template selection systemsin accordance with the first and second aspects of the presentinvention, since a template data storage means in which template datarepresenting a plurality of templates representing a plurality ofartificial bones of different shapes is stored in the form of electronicdata is used, management of the templates becomes unnecessary.

[0032] Further, in both the artificial bone template selection systemsin accordance with the first and second aspects of the presentinvention, when an image processing means which carries out imageprocessing on at least one of the images displayed by the display meansso that their shapes can be more clearly discriminated is provided andthe image processed by the image processing means is displayed in theprocessed condition, the bone image and the image of the prospectivetemplate can be easily discriminated from each other, which permits theoperator to more accurately locate the images with respect to each otherin a short time. Further, a template most optimal to the bone can beeasily and quickly selected, and at the same time, relative positionbetween the images can be more finely adjusted, whereby most optimaltemplate can be surely selected.

[0033] Further, when the artificial bone template system is providedwith an order information output means which outputs, information forordering artificial bone corresponding to the template selected by theprospective template selection means, an automatic artificial bone ordersystem which automatically orders artificial bone as soon as theprospective template selection processing can be realized. When thesystem is incorporated in a network such as using the internet, the usersuch as a doctor, a medical engineer and the like can directly tradewith a maker or an agency without intervening therebetween a broker.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034]FIG. 1 is a block diagram showing an artificial bone templateselection system in accordance with a first embodiment of the presentinvention,

[0035]FIG. 2 is a schematic view showing an appearance of the artificialbone template selection system shown in FIG. 1,

[0036]FIG. 3 is an enlarged view of a part including a femur as a boneto be replaced,

[0037]FIG. 4 is a view showing an example of the frame on the basis ofwhich the template selection processing is carried out,

[0038]FIG. 5 is a block diagram showing an artificial bone templateselection system in accordance with a second embodiment of the presentinvention,

[0039]FIG. 6 is a view for illustrating a method of designating on thedisplayed bone image a feature point representing the shape of the bone,

[0040]FIG. 7 is a block diagram showing in detail the template datastorage means,

[0041]FIG. 8 is a view showing an example of the structure of templatedata, and

[0042]FIGS. 9A and 9B are views showing another example of the structureof template data.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] In FIG. 1, an artificial bone template selection system 1 inaccordance with a first embodiment of the present invention comprises atemplate data storage means 10 in which template data representing aplurality of templates representing a plurality of artificial bones ofdifferent shapes is stored, a bone shape measuring means 20 whichmeasures the shape of bone to be replaced by artificial bone on thebasis of bone image data S1 representing an image including the bone tobe replaced by artificial bone, a prospective template selection means30 which selects, as a prospective template, at least one template theshape of which substantially conforms to the shape of the bone to bereplaced by artificial bone as measured by the bone shape measuringmeans 20 out of the plurality of templates represented by the templatedata, a display means 40 (e.g., a CRT or a liquid crystal panel) whichdisplays the bone image representing the shape of the bone to bereplaced by the artificial bone and an image of the prospectivetemplate(s) selected by the prospective template selection means 30, animage processing means 50 which carries out image processing on theimages displayed by the display means so that their shapes can be moreclearly discriminated from each other, a display control means 60 whichcauses the display means 40 to display the bone image and the image ofthe prospective template superposed one on another on the basis of theprocessed image data, and an order information output means 70 whichoutputs order information for ordering artificial bone for replacing thebone.

[0044] The artificial bone template selection system 1 further comprisesa shaping means 80 which deforms, on the screen of the display means 40,the shape of a standard template represented by template data read outfrom the template data storage means 10, a storage means 81 which storesdifference data D3 representing the difference in shape between thestandard template and a deformed template obtained by deforming thestandard template by the shaping means 80, and an input means 90(consisting of a keyboard 91, a dial 92, a mouse 93 and the like) forinputting data for selecting a more desirable template out ofprospective templates and/or for carrying out various operations.

[0045] As shown in FIG. 2, the display means 40, the input means 90 andthe like are placed on a table 2, and the template data storage means10, the bone shape measuring means 20 and the like are contained in abody 3 under the table 2.

[0046] The template data storage means 10 comprises, for instance, amagnetic recording device such as a hard disc which reads out templatedata from a computer-readable portable recording medium such as a CD-ROMor a MO and temporarily stores the template data read out. When thespeed of the selection (retrieval) to be described later does notinvolve a problem, the template data may be read out from thecomputer-readable portable recording medium such as a CD-ROM or a MO onthe spot.

[0047] The template data comprises an image file in which a plurality ofpieces of image data each representing one template are recorded and ashape data file in which a plurality of pieces of template shape data D1each representing a feature of the shape of a template are recorded incorrelation with the image data for the template. The image fileincludes, in addition to life-size images of the standard templates,thumbnail images (scale-down images) of the standard templates (e.g.,reduced ⅛ by ⅛).

[0048] By storing template images in the form of electronic data,whether each template conforms in shape to the bone to be replaced canbe checked on the basis of electronic data and the necessity of keepingnumerous templates at hand and managing the templates can be eliminated.

[0049] In this particular embodiment, vector data representing ageometrical feature is employed as the shape data D1. In the case of afemur, the diameter of the bone head, the length of the bone shaft, thelength of the bone holder between the bone head and the bone shaftand/or the angle between the bone shaft and the bone holder can beemployed as the vector data. With this arrangement, a database forfacilitating retrieval and shape matching can be obtained.

[0050] The bone shape measuring means 20 comprises a measuring section21 which measures the shape of the bone to be replaced on the basis ofthe image data S1, and a storage section 22 which stores bone shape dataD2 representing the shape of the bone measured by the measuring section21.

[0051] The prospective template selection means 30 carries out selection(retrieval) for selecting a standard template, which conforms to theshape of the bone to be replaced, on the basis of the bone shape data D2obtained by measuring the bone (read out from the storage section 22)and the template shape data D1 read out from the template data storagemeans 10.

[0052] The image processing means 50 carries out image processing forfacilitating discrimination between the shape of the template and theshape of the bone. For example, the image processing means 50 carriesout image processing, during or after selection of the standardtemplate, for displaying the edge of the bone and/or the template onlyin line, shading the image, displaying contour lines, displaying theoverall shapes the bone and/or the template in a wire frame fashion orenhancing the edge of one of the bone and the template.

[0053] The display control means 60 sets layout of the frame of thedisplay means 40 so that a template display area, where a list ofprospective templates automatically selected by the prospective templateselection means 30 and/or thumbnail images of the prospective templatesis displayed and a bone image display area, where an image of the boneis displayed, are provided side by side. Further, the display controlmeans 60 causes the display means 40 to display the image of the boneand the image of the template (the processed image, when it has beenprocessed by the image processing means 50) in the template display areasuperposed one on another.

[0054] In the superposed display, all the prospective templates may beautomatically located to be superposed on the image of the bone or onlyone or more of the prospective templates selected by the operator out ofthe prospective templates automatically selected by the prospectivetemplate selection means 30 may be superposed on the image of the bone.In the latter case, the prospective template(s) may be located under theinstruction of the operator.

[0055] By thus setting the template display area and the bone imagedisplay area, the image of the bone and the list of the prospectivetemplates (with the thumbnail images of the prospective templates) canbe displayed simultaneously, and a final most optimal template can beselected at high efficiency out of a plurality of prospective templatesautomatically selected by the prospective template selection means 30.

[0056] Operation of the artificial bone template selection system 1 ofthis embodiment will be described, hereinbelow.

[0057] It is consumed here that a femur 9 (FIG. 3) is to be replaced byartificial bone, and a radiation image (CR image) including the image ofthe femur 9 is taken by a CR (computed radiography) system. That is,X-rays are projected through an object onto an imaging plate comprisingstimulable phosphor so that a radiation image of the object is recordedon the imaging plate as a pattern of stored radiation energy. Then theradiation image recorded on the imaging plate is read out and bone imagedata Si is obtained. The bone image data S1 is input into the artificialbone template selection system 1 of this embodiment.

[0058] The display control means 60 causes the display means 40 todisplay a femur 9 with a lost part 9 a together with bones 7 and 8around the femur 9 in the bone image display area on the basis of thebone image data S1 as shown in FIG. 4.

[0059] The bone image data S1 is input also into the measuring section21 of the bone image measuring system 21. The measuring section 21extracts the edge of the femur 9 with the lost part 9 a by a knownmethod and stores bone shape data representing the outer shape of thefemur 9 in the storage section 22. The bone shape data D2 is in the sameformat as the template shape data D1 stored in the template data storagemeans 10. In this particular embodiment, since the template shape dataD1 is vector data, the measuring section 21 obtains vector datarepresenting the diameter of the bone head 9 b, the length of the boneshaft 9 c, the length the bone holder 9 d and/or the angle between thebone shaft 9 c and the bone holder 9 d and stores the vector data in thestorage section 22 as the bone shape data D2.

[0060] The information specifying the bone 9 with the lost part 9 a tobe replaced by artificial bone may be extracted from a menu codeattached to the bone image data SI or may be specified by the operatordesignating a point with the mouse 93 on the frame of the display means40.

[0061] Thereafter, the prospective template selection means 30 reads thetemplate shape data D1 of templates for a femur from the template datastorage means 10, and selects one or more templates whose outer shapeconforms to the contour of the femur 9 of the patient on the basis ofthe bone image data S1. The selection may be based on a pattern matchingbetween the two pieces of image data in a raster form. However, it ispreferred that the selection be carried out on the basis of comparisonbetween the template shape data D1 and the bone shape data D2. That is,since the template shape data D1 and the bone shape data D2 are bothvector data representing the diameter of the bone head 9 b, the lengthof the bone shaft 9 c, the length the bone holder 9 d and/or the anglebetween the bone shaft 9 c and the bone holder 9 d, the selection(retrieval) can be done in a shorter time as compared with when theselection is done by simple pattern matching on the raster data.

[0062] The prospective template selection means 30 determines whethereach of the standard templates for a femur conforms to the femur 9 withthe lost part 9 a, and automatically selects one or more of the standardtemplates whose difference from the affected femur 9 is within apredetermined range. When there is no standard template whose differencefrom the affected femur 9 is within the predetermined range, theprospective template selection means 30 selects one or more of thestandard templates close to the predetermined range. In this manner, theprospective template selection means 30 selects at least one standardtemplate as a prospective template.

[0063] The prospective template selection means 30 inputs into thedisplay control means 60 information J1 on the prospective template(s)selected. The display control means 60 causes the display means 40 todisplay the numbers of the prospective templates selected (e.g.,template A to template D) together with the thumbnail images thereof inthe template image display area. It is preferred that the thumbnailimages be read out from the template data storage means 10. When thethumbnail images are not prepared in advance, they are obtained byreducing the original image.

[0064] In addition to the numbers and the thumbnail images of theprospective templates, information on the maker, model number and thelike of the artificial bone represented by the prospective templates maybe read out from the template data storage means 10 and displayed in thetemplate display area.

[0065] Further, the list of the prospective templates (e.g., the numberof the prospective templates, the model number of the same, and thelike) may be output on a recording medium such as paper as well beingdisplayed by the display means 40.

[0066] The operator or the doctor determines whether the automaticselection is satisfactory on the basis of the list and/or the thumbnailimages of the selected prospective templates. When the automaticselection is satisfactory, the operator inputs the effect that theautomatic selection is satisfactory into the artificial bone templateselection system 1.

[0067] It is possible to check whether the automatic selection issatisfactory by superposing the prospective templates (limited innumber) on the CR film image of the affected bone 9. Also in this case,since the number of the prospective templates has been reduced by theautomatic selection, the checking can be done in a shorter time.

[0068] When it is determined that the automatic selection isunsatisfactory or when it is required to further reduce the number ofthe prospective templates (e.g., to 1), the bone image data S1 isanalyzed in further detail, and templates which further conform to thebone in shape are selected out of the prospective templates. Thisselection may be done in the following manner by operating the keyboard91, the mouse 93, the dial 92 and the like viewing the screen of thedisplay means 40.

[0069] That is, the display means 40 is caused to display a templateselection frame such as shown in FIG. 4. Then, the operator selects oneof the templates in the list of prospective templates (or the thumbnailimages thereof) displayed in the template display area on the screen ofthe display means 40. This selection may be done by pointing with themouse 93 the template to be selected or by inputting the number of thetemplate to be selected through the keyboard 91.

[0070] When one of the prospective templates is selected, theprospective template selection means 30 reads out image datarepresenting the selected prospective template in an original size fromthe template data storage means 10 and inputs it into the imageprocessing means 50. Then the display control means 60 causes thedisplay means 40 to display an image of the selected prospectivetemplate in the original size.

[0071] Thereafter, the image of the selected prospective image in theoriginal size is moved to the image of the bone 9 to be replaced byartificial bone and superposed thereon. This operation of superposingthe image of the selected prospective image in the original size on theimage of the bone 9 to be replaced is preferably done by drag and dropwith the mouse 93.

[0072] At this time, it is preferred that image processing means 50carries out image processing for facilitating discrimination between theshape of the prospective template and the shape of the bone. Forexample, the image processing means 50 carries out image processing forenhancing edges of the images, shading the one of the images, displayingthe edge of the bone and/or the template only in line (solid line ordotted line), displaying the overall shapes the bone and/or the templatein a wire frame fashion, or displaying the images in different colors.If required, the images may be displayed in an enlarged size so thatwhether the selected prospective template well conforms to the bone tobe replaced can be visually checked more easily and superposing accuracyis increased.

[0073] The image of the selected prospective template moved to the imageof the bone is finely moved up and down and right and left and finelyrotated so that the image of the selected prospective template conformsto the image of the bone to be replaced in position, inclination and thelike. These operation is preferably carried out by designating atranslating movement mode or a rotational movement mode by the keyboard91 and moving the image of the selected prospective template by adistance or an angle corresponding to the amount of rotation of the dial92.

[0074] This process is repeated while changing the prospective templatesand selecting a prospective template most suitable for the bone 9 to bereplaced. In this manner, information on a final prospective template isstored in the storage means 81.

[0075] When the bone 9 is not to be replaced in whole but artificialbone is embedded only in place of the lost part 9 a of the femur 9,geometrical data such as coordinates of the edge 9 f (FIG. 3) of thelost part 9 a of the femur 9 for defining the lost part 9 a on theprospective templates is also stored in the storage means 81.

[0076] If desired, the template shape data D1 on the final prospectivetemplate is input into the shaping means 80 and the prospective templateis slightly enlarged or reduced in whole or a part of the template isfinely deformed so that the final prospective template is adjusted to ashape which strictly conforms to the shape of the bone 9 to be replaced.Then difference data D3 representing the difference of the shape of thefinal prospective template after the adjustment from that before theadjustment is stored in the storage means 80.

[0077] The fine deformation of only a part of the final prospectivetemplate is preferably carried out by first designating the part to bedeformed with the mouse 93, designating a translating movement mode or arotational movement mode by the keyboard 91 and then deforming thedesignated part by a value corresponding to the amount of rotation ofthe dial 92. Such a local deformation can be carried out by changingcoordinate parameters and/or function parameters which define the shapeof the template and are obtained on the basis of the template shape dataD1.

[0078] The amount of movement of the image of the template or the amountof change of the parameters when the image of the template is to bemoved or the template is to be partly deformed can be set also byinputting numerical values through the keyboard 91.

[0079] The operation of deforming the template or moving the image ofthe template can be easily carried out when the image of the bone to bereplaced and the image of the template are displayed superposed one onanother. Further since such operation is carried out only on templateswhich have been automatically selected on the basis of the image data,selection of a suitable template can be carried out in a shorter time.

[0080] Then an order file for ordering artificial bone corresponding tothe template thus selected, e.g., maker model number (template number),number of the templates, delivery time, place of delivery, thedifference data D3, and the like, is made by the order informationoutput means 70 and the order file is sent to a maker or an agency.

[0081] An artificial bone template selection system in accordance with asecond embodiment of the present invention will be described withreference to FIGS. 5 and 6, hereinbelow.

[0082] In the artificial bone template selection system in accordancewith the second embodiment of the present invention, feature points aredesignated on the image of the bone to be replaced and the bone shapedata D2 representing the shape of the bone to be replaced is obtained onthe basis of the designated feature points.

[0083] In this embodiment, as the means for designating the featurepoints on the image displayed by the display means 40, a pointing devicesuch as a mouse 93 is employed, and a bone shape specifying means 26,which obtains as vector data the bone shape data D2 on the basis of thedesignated feature points, is provided in place of the bone shapemeasuring means 20 employed in the first embodiment.

[0084] In the artificial bone template selection system 1 of the secondembodiment, the operator designates feature points on the image of thebone displayed by the display means 40. This designation may be carriedout, for instance, by designating the diameter of the bone head 9 b bypointing the center 9 g and the edge 9 h of the bone head 9 b,designating the length of the bone shaft 9 c by pointing thelongitudinal ends 9 m and 9 n, designating the length of the bone holder9 d by pointing the longitudinal ends 9 j and 9 k and designating theangle θ between the bone shaft 9 c and the bone holder 9 d by pointingthe longitudinal ends 9 m and 9 n of the bone shaft 9 c and thelongitudinal ends 9 j and 9 k of the bone holder 9 d. The bone shapespecifying means 26 obtains as vector data the bone shape data D2 on thebasis of the designated feature points. The prospective templateselection means 30 selects at least one of the standard templates as aprospective template in the same manner as that employed in the firstembodiment.

[0085] Since pointing the feature points with the mouse 93 can beintuitively done observing the image of the bone displayed on thedisplay means 40, the shape of the bone can be suitably specified evenif the bone is complicated in shape and selection of the artificial bonetemplate can be automatically carried out.

[0086] Though preferred embodiments of the present invention aredescribed above, the present invention need not be limited to theembodiments described.

[0087] For example, though, in the embodiments described above, the boneshape data D2 is obtained as vector data and whether the templateconforms in shape to the bone to be replaced is checked by the use ofthe bone shape data D2 in the form of vector data and the template shapedata D1 also in the form of vector data, whether the template conformsin shape to the bone to be replaced is checked by pattern matching bythe use of raster data representing the bone to be replaced and rasterdata representing the standard template.

[0088] Further, after prospective templates are automatically selectedby the prospective template selection means 30, images of all theprospective templates may be superposed on the image of the bone to bereplaced by automatic alignment processing and which of the prospectivetemplates is the best may be determined viewing the superposed image.

[0089] In this case, when the prospective template selection means 30selects a plurality of prospective templates, it is preferred that thecontours of the image of the bone and the prospective templates bedisplayed in a wire frame fashion and the wire frames for the respectiveimage be displayed in different colors.

[0090] Further, when the prospective template selection means 30 selectsa plurality of prospective templates, it is possible to set a displayarea for each prospective template and display a superposed image ineach display area.

[0091] Prospective templates can be clearly discriminated from eachother by the use of such a layout.

[0092] As the image data S1 representing an image including the bone tobe replaced by artificial bone, image data obtained by reading out animage on X-ray film by an image scanner, cross-sectional image dataobtained by CT or MRI, three-dimensional image data obtained byreconfiguration, or the like may be employed in place of a radiationimage read by a CR system.

[0093] The template data storage means 10 will be described in moredetail with reference to FIGS. 7 to 9B, hereinbelow.

[0094] As shown in FIG. 7, the template data storage means 10 comprisesa recording section 11 which records data on a predetermined recordingmedium and a recording section 15 which reads out data from therecording medium. The recording section 11 comprises an image filerecording means 12 which records a plurality of pieces of template imagedata D4, each piece representing an image of one template, in an imagefile, a shape data extracting means 13 which extracts a plurality ofpieces of template shape data D1, each representing a feature of theshape of a template, on the basis of template image data D4 on eachtemplate, and a shape file recording means 14 in which the pieces oftemplate shape data D1 extracted by the shape data extracting means 13are recorded in correlation with the template image data for eachtemplate.

[0095] The recording medium employed in the recording section 11 or thereading section 15 may be a computer-readable portable recording mediumsuch as a CD-ROM, CD-RAM, DVD-ROM, DVD-RAM or a MO as well as a fixedtype magnetic recording medium such as a hard disc.

[0096] The reading section 15 is provided with a recording/reading means16 which reads out template data recorded on a portable recording mediumsuch as a CD-ROM, MO or the like and temporarily stores the templateshape data read out from the portable recording medium in a recordingmedium such as a hard disc.

[0097] When a hard disc is employed as the recording medium in therecording section 11, the processing of reading out the template shapedata becomes unnecessary. When the speed of the selection (retrieval) tobe described later does not involve a problem, the template data may beread out from the computer-readable portable recording medium such as aCD-ROM or a MO each time required.

[0098] The recording section 11 and the reading section 15 may comprise,for instance, a computer system using a CPU.

[0099] As shown in FIG. 8, the template data comprises an image file inwhich a plurality of pieces of image data D4 each representing onetemplate are recorded and a shape file in which a plurality of pieces ofshape data D1 each representing a feature of the shape of a template arerecorded in correlation with the image data D1 for the template. It ispreferred that the image file includes, in addition to life-size imagesof the standard templates, thumbnail images (scale-down images) of thestandard templates (e.g., reduced ⅛ by ⅛).

[0100] Further, the template data is provided with a table file fortaking a correspondence between each standard template and the filenumber of the image file and the shape file for the standard template.Further in order to facilitate, the image files and the shape files aregrouped by part, e.g., humerus, knee joint and the like.

[0101] As the template shape data D1, vector data representing thediameter of the bone head, the length of the bone shaft, the length ofthe bone holder between the bone head and the bone shaft and/or theangle between the bone shaft and the bone holder can be employed. Withthis arrangement, not only the images of templates are simply stored inthe form of electronic data but also a database for facilitatingretrieval and shape matching can be obtained.

[0102] Creation of a database on the template data will be described,hereinbelow.

[0103] The image file recording means 12 makes an image file in which aplurality of sets of template image data D4 obtained by reading imagesof a plurality of standard templates with an image scanner or the like,and stores the image file in the recording medium such as a hard disc ora CD-ROM. It is preferred that thumbnail images of each standardtemplate be included in the image file in addition to the original imageof the standard template as described before. It is further preferredthat the image data be compressed by a known image compression methodsuch as JPEG.

[0104] The shape data extracting means 13 measures the contour shape ofeach standard template by analyzing the image data D4 on the template.Then the shape data extracting means 13 obtains vector data representingthe feature of the contour shape of each template and inputs the vectordata into the shape file recording means 14 as the template shape dataD1. For example, in the case of templates for the femur, sets of datarespectively representing the diameter of the bone head, the length ofthe bone shaft, the angle between the bone shaft and the bone holder,the length of the bone holder, and the like are taken as the vectordata.

[0105] It is possible to eliminate the shape data extracting means 13.In this case, the operator manually measures the vector data of eachstandard template with a scale or the like, and inputs the data thusobtained into the template data storage means 10 through the keyboard91.

[0106] The shape file recording means 14 makes a table file whichcorrelates the template shape data D1 and the template image data D4with each other while grouping them by part, and records the table fileand the shape file thus made on the recording medium such as a CR-ROM.

[0107] The template data storage means 10 may be variously modified.

[0108] In one modification of the template data storage means 10,template data of the structure shown in the following table is prepared,and the contour shape of the standard template can be expressed bygenerating a curve such as a spline curve on the basis of control pointswhile referring to information on the coordinate train of the controlpoints, whether the control points are on an edge, and the like. TABLE 1data structure of template 1) model number femur (left), femur (right)2) size #7, #8, #9, #10 3) direction front , side 4) contour outer edge,inner edge 5) reference line centerline, bone head axis 6) referencepoint bone head fixing position; 0 mm, 5 mm, 10 mm 7) the others 1:material, weight, price, maker, scale 2: notes

[0109] With this data structure, when the scale of an image of atemplate is varied in order to apply the image of the template to adisplayed image of the bone to be replaced by artificial bone, the edgeof the image of the template is smoothly displayed as shown in FIGS. 9Aand 9B, whether the template is suitable for the bone can be easilychecked.

[0110] When the degree of suitability is automatically calculated,simple digitization of the image of the template generates digitizationerrors. However, with the method described above, calculation errors canbe suppressed.

What is claimed is:
 1. An artificial bone template selection systemcomprising a template data storage means in which template datarepresenting a plurality of templates representing a plurality ofartificial bones of different shapes is stored, a bone shape measuringmeans which measures the shape of bone to be replaced by artificial boneon the basis of bone image data representing an image including the boneto be replaced by artificial bone, and a prospective template selectionmeans which selects, as a prospective template, at least one templatethe shape of which substantially conforms to the shape of the bone to bereplaced by artificial bone as measured by the bone shape measuringmeans out of the plurality of templates represented by the templatedata.
 2. An artificial bone template selection system as defined inclaim 1 further comprising a display means which displays the bone imagerepresenting the shape of the bone to be replaced by the artificial boneand an image of the prospective template(s) selected by the prospectivetemplate selection means and a display control means which causes thedisplay means to display the bone image and the image of the prospectivetemplate superposed one on another.
 3. An artificial bone templateselection system as defined in claim 2 in which an image processingmeans which carries out image processing on at least one of the imagesdisplayed by the display means so that their shapes can be more clearlydiscriminated is provided, and the display control means causes thedisplay means to display the image processed by the image processingmeans in the processed condition.
 4. An artificial bone templateselection system as defined in claim 1 further comprising an orderinformation output means which outputs information for orderingartificial bone corresponding to the template selected by theprospective template selection means.
 5. An artificial bone templateselection system comprising a template data storage means in whichtemplate data representing a plurality of templates representing aplurality of artificial bones of different shapes is stored, a boneimage display means which displays the bone image representing the shapeof the bone to be replaced by the artificial bone, a feature pointdesignating means which designates on the bone image displayed by thebone image display means a feature point representing the shape of thebone, a bone shape specifying means which specifies the shape of thebone on the basis of the feature point designated by the feature pointdesignating means, and a prospective template selection means whichselects, as a prospective template, at least one template the shape ofwhich substantially conforms to the shape of the bone specified by thebone shape specifying means out of the plurality of templatesrepresented by the template data.
 6. An artificial bone templateselection system as defined in claim 5 further comprising a displaycontrol means which causes the display means to display the bone imageand the image of the prospective template superposed one on another. 7.An artificial bone template selection system as defined in claim 6 inwhich an image processing means which carries out image processing on atleast one of the images displayed by the display means so that theirshapes can be more clearly discriminated is provided, and the displaycontrol means causes the display means to display the image processed bythe image processing means in the processed condition.
 8. An artificialbone template selection system as defined in claim 5 further comprisingan order information output means which outputs information for orderingartificial bone corresponding to the template selected by theprospective template selection means.
 9. An artificial bone templatedisplay system comprising a template data storage means in whichtemplate data representing a plurality of templates representing aplurality of artificial bones of different shapes is stored, a displaymeans which displays an image, and a display control means which causesthe display means to display the bone image and an image of at least oneof the templates stored in the template storage means superposed one onanother.
 10. An artificial bone template display system as defined inclaim 9 in which an image processing means which carries out imageprocessing on at least one of the images displayed by the display meansso that their shapes can be more clearly discriminated is provided, andthe display control means causes the display means to display the imageprocessed by the image processing means in the processed condition. 11.An artificial bone template display system as defined in claim 9 furthercomprising an order information output means which outputs informationfor ordering artificial bone corresponding to the template selected bythe prospective template selection means.
 12. An artificial bonetemplate storage system comprising an image file recording means whichrecords a plurality of pieces of template image data, each piecerepresenting an image of one template, in an image file, and a shapefile recording means which records a plurality of pieces of templateshape data representing geometric features of each of the templates in ashape file in correlation with the template image data for eachtemplate.
 13. An artificial bone template storage system as defined inclaim 12 further comprising a shape data extracting means which extractsa plurality of pieces of template shape data, each representing afeature of the shape of a template, on the basis of template image dataon each template.
 14. An artificial bone template storage system asdefined in claim 12 in which the shape data is in the form of vectordata.
 15. A computer-readable recording medium for storing template datarepresenting a plurality of templates representing a plurality ofartificial bones of different shapes in which are recorded an image filein which a plurality of pieces of image data each representing oneartificial bone template are recorded and a shape file in which aplurality of pieces of shape data each representing a feature of theshape of an artificial bone template are recorded in correlation withthe image data for the template.
 16. A computer-readable recordingmedium as defined in claim 15 in which the shape data is in the form ofvector data.